New Review Highlights How Storage Choices Affect Spruce Timber Quality

As climate change increases the frequency of storms, droughts and bark beetle outbreaks across Europe, forest managers are often faced with large volumes of spruce timber that cannot be processed immediately. Effective interim storage has therefore become an increasingly important tool for protecting timber value and ensuring a stable wood supply.

A new OptiForValue publication in Wood Material Science & Engineering, “Roundwood Storage Methods and Their Effect on Spruce Wood Quality: A Review”, synthesises findings from 68 studies spanning six decades to examine how different storage approaches influence the quality of spruce roundwood.

The study shows that timber quality during storage is largely determined by three key factors: moisture, oxygen, and temperature. These conditions influence whether wood dries out, develops cracks, becomes discoloured or is attacked by fungi and insects.

The review found that:

• Dry storage is inexpensive and easy to implement but is generally suitable only for short-term storage because wood quality can deteriorate rapidly.
• Wet storage and airtight foil storage are the most effective options for preserving wood quality over extended periods, although they require greater investment, infrastructure and management.
• Cold storage can effectively protect timber quality during winter, but its applicability is limited by climate and season.
• Leaving timber standing or relying on storm-felled trees to remain physiologically active can temporarily delay degradation, but these are not reliable long-term solutions.

Importantly, the authors highlight that timber degradation is not only a visible problem. While fungi and insects are often responsible for the most obvious damage, storage can also trigger chemical changes within the wood that may affect downstream processing and product quality.

The review concludes that there is no single best storage method. Instead, selecting the most appropriate strategy requires balancing preservation effectiveness, cost, environmental considerations and operational constraints.

The review also highlights emerging approaches that could further improve timber preservation in the future. These include environmentally friendly antifungal treatments, biological control agents, and bio-based protective covers that may help reduce wood degradation while lowering environmental impacts. Although promising, these solutions require further research before they can be widely adopted in commercial forestry operations.

For projects such as OptiForValue, which seek to improve the sustainable utilisation and value recovery of forest resources, these findings provide important insights into how timber can be managed and preserved during periods of supply disruption.

Read the full publication:
Roundwood Storage Methods and Their Effect on Spruce Wood Quality: A Review